1. Field of the Invention
In general, the present invention relates to an image displaying system for displaying an image signal by modifying a display attribute of the image signal. In particular, the present invention relates to an effective technology applied to an image displaying system for displaying an image signal, such as text data and dynamic-image data output by an information processing apparatus, on a display screen of an image displaying apparatus, whereby the contrast of the image signal is modified in accordance with the type of the data to be displayed.
2. Description of the Related Art
In recent years, the performance of computers, and in particular, the performance of personal computers (PCs) has exhibited rapid progress, becoming capable of handling not only static images but also dynamic images. In addition, multimedia services such as video on demand (VOD), which allows the user to watch a desired program at any convenient time; an electronic encyclopedia using a CD-ROM; and the generation of dynamic images using a DVD (digital video (or versatile) disk) are becoming popular.
In such a multimedia service, dynamic-image data (such as a television image) may be displayed on a display screen of an image displaying apparatus for displaying computer text and graphics. The display screen of a CRT (cathode ray tube) display unit or an LCD (liquid-crystal display) unit, which is connected to a computer and used as an image displaying apparatus for displaying an image signal output by the computer, has good precision, but in general has its display contrast set at a low value in comparison with a television receiver.
For example, let us compare the value of the peak contrast of a television receiver with that of an image displaying apparatus. The value of the peak contrast of a television receiver is normally at least 300 cd/m2. On the other hand, the value of the peak contrast of an image displaying apparatus for displaying an image based on an image signal output by a computer is about 150 cd/m2, a low value which is about half that of the peak contrast of a television receiver.
Such a contrast value is good in that it does not cause fatigue to the eyes of the user who spends a long period of time on the composition of a text or work such as CAD (Computer Aided Design) by using a computer. For displaying a dynamic image described above, however, the contrast value of the screen of the image displaying apparatus provides an appearance inferior to a television receiver, becoming a negative factor in the image display.
In order to solve the problem described above, an image displaying apparatus has been proposed, which has an additional switching means for manually increasing the display contrast of the entire image displaying apparatus employed in the conventional computer over the entire display screen (for example, in a case of displaying a dynamic image thereon).
The conventional control of display brightness, an item of adjustment like the one described above, includes adjustment of contrast, adjustment of brightness, and control of the amplitudes of a variety of color image signals, such as the red, blue, and green color signals. The adjustment of contrast, the adjustment of brightness, and the control of amplitudes can all be controlled for the entire display screen. However, the control of contrast on only part of the display screen for a dynamic-image portion or the like has not been prescribed.
In addition, window-luminance adjusting systems capable of individually adjusting the luminance of a specified window are disclosed in Japanese Patent Laid-open Nos. Sho 61-248083, Sho 63-158587, Hei 4-220691, Hei 7225575 and Hei 8-251503. In each of these window-luminance adjusting systems, however, the distribution of functions between the image displaying apparatus and the information processing apparatus for generating an image signal is not clarified.
When displaying a computer image as a window on the conventional image displaying apparatus, as is the general practice with the contemporary computer, dynamic images are displayed only on some windows of the display screen while the remaining windows are used for doing work such as composition of a text. Since the contrast of the entire display screen is controlled, even in such a case, the entire display screen becomes bright. As a result, in a state where a dynamic image is displayed while the user is doing work such as composition of a text, the amount of fatigue caused to the eyes of the user may increase.
In order to solve the problems described above, the present invention provides a technology that clarifies the distribution of functions among the image displaying apparatus, the information processing apparatus, and an operating system controlling the operations of the information processing apparatus. The present invention is capable of displaying data with a display attribute varying from area to area on the display screen of the image displaying apparatus.
In an image displaying system wherein an image signal is transmitted from an information processing apparatus to an image displaying apparatus to be displayed on the image displaying apparatus, the invention generates area-attribute information for modifying a display attribute of a specific area on a display screen of the image displaying apparatus. The area-attribute information generated in the information processing apparatus is transmitted from the information processing apparatus to the image displaying apparatus through a communication means. The display attribute of the specific area on the display screen of the image displaying apparatus is modified in accordance with the area-attribute information received by the image displaying apparatus, and the data is displayed on the display screen.
In the image displaying system described above, display attributes for special-type data, such as dynamic-image data, and for a special display element, such as an active window, are prepared in advance. Area-attribute information is generated, which comprises area information indicating a specific area on a display screen of the image displaying apparatus in which the data is to be displayed, and information on the display attributes prepared in advance is generated.
Then, a specific-area-display-attribute changing means changes a display attribute of data to be displayed in a specific area indicated by the area information of the generated area-attribute information, and the data is displayed in the specific area of the display screen of the image displaying apparatus.
As described above, according to the image displaying system provided by the present invention, area-attribute information is generated by the information processing apparatus for data to be displayed on the image displaying apparatus, and the data is displayed in a specific area of the display screen of the image displaying apparatus indicated by the area-attribute information by modifying a display attribute of the specific area in accordance with the area-attribute information.
As a result, in the image displaying system, the distribution of functions among the image displaying apparatus, the information processing apparatus, and an operating system controlling the operations of the information processing apparatus is clarified. In addition, the image displaying system is capable of displaying data with a display attribute varying from area to area on the display screen of the image displaying apparatus.